Scientific Research Does Document an Effective Treatment for Autism
Published research indicates that active participation in intensive, high-quality intervention based on applied behavior analysis (ABA) results in measurable and significant progress for almost all children diagnosed with autism. Virtually all children will acquire important skills through ABA intervention and some will acquire enough skills that their behavior no longer meets the clinical definition of autism. There are indeed children who no longer qualify for a diagnosis of autism based on the improvement and gains made and the absence of the very behaviors that led to the initial diagnosis. The most rigorously controlled studies have yielded this best outcome in the range of 30 to 45 percent of those treated; however, even the children who retain their diagnosis gain important skills that lead to greater independence and success through early, intensive behavioral intervention.
Where is the scientific support for the methods demonstrated to achieve these outcomes? As mentioned above, there is an emerging set of research published in peer reviewed journals that documents the effectiveness of intensive ABA intervention in the treatment of autism. Please note the non-exhaustive list below. Currently, we know that early intervention using ABA, that is intensive in nature and duration, leads to better outcomes. Nonetheless, more research is needed to identify and tease out key elements of ABA intervention most likely to produce best outcomes (in other words, to tease out various levels of intensity, duration, and other treatment parameters such as setting). Research with older students and research that examines the impact of early intensive intervention on neuroanatomy and neural processes would also be illuminating. Most importantly, even more effective procedures are needed to better treat the majority of children who are not yet considered best outcomes.
Although the research underlying ABA is solid, the demand for services currently exceeds the supply of qualified providers. Consumers are faced with an array of possible providers, some more qualified than others. For those parents and other consumers interested in applied behavior analysis, I have listed a number of resources to guide efforts to find a qualified provider.

I have seen the effects of behavior therapy. It helps, but only to the point that the autistic brain is receptive. The more profoundly autistic don't go very far with it. That means that
The next step has to be medical.